The success of chemotherapeutic treatment of cancer is not the same for each patient, cancer type, or treatment type. In the case that the treatment does not have an optimal result, it may be possible to take action to improve the situation, for example by adapting the treatment regimen. To this effect, the therapy response of a tumor can be monitored during the therapy. Medical imaging, e.g. magnetic resonance (MR) imaging, provides data from which the therapy response of a tumor can be deduced. For example, MR scans may be taken before treatment and after at least part of the treatment has been performed. This way, the tumor may be tracked over time and the response to the treatment can be assessed. For example, the size of a tumor may be measured using a medical workstation. However, currently used manual measurements are of limited robustness and reproducibility. Tracking a tumor over time requires it to be found and labeled in the image data, which is a time-consuming process.
The paper “Quantitative imaging to assess tumor response to therapy: common themes of measurement, truth data, and error sources” by C. R. Meyer et al., Translational Oncology, Vol. 2, No. 4, December 2009, pp. 198-210, discloses multiple, image modality-independent means to assess the relative performance of algorithms for measuring tumor change in response to therapy.
U.S. Pat. No. 7,708,682 B2 discloses a method and an apparatus for planning radiation therapy. A radiation dose distribution is adapted on the basis of shape and position variations of the organs of interest, determined from a comparison of a first image and a second image taken at different points in time during the radiation treatment process. A surface mesh is first adapted to the surface of the object of interest in the first image and then to the surface of interest in the second image. Then, a difference between the two adapted surface meshes is determined.